The present invention relates to a device for acquiring operating parameters of an electric motor, such as a number of motor starts and a number of operating hours, and optionally for acquiring other operating characteristics of an electric motor to provide reliable information regarding whether the electric motor can be reused after a certain operating time or must be discarded.
Electric A.C. or D.C. motors used in conventional engineering systems may under some circumstances be reusable in a new engineering system at the end of the lifetime of the engineering system if the service time of the customer""s electric motor is considerably shorter than the manufacturer""s indicated useful life. A procedure to reuse the electric motor (i.e., controlled product recycling) is already being utilized for copiers, for example. However, such recycling has previously required extensive testing to permit reusability to be reliably determined. For example, to use this procedure with the copiers as described above, an expensive acoustic noise analysis is performed to obtain a reliable statement about product recycling. With electric motors, it has been customary to perform extensive measurements in an expensive procedure, and to also (optionally) perform stress tests to be able to obtain a statement regarding product recyclability.
The present invention uses a completely different procedure and provides a device for acquiring operating parameters on electric motors with means (e.g., an arrangement) being influenced by at least one operating parameter. This means is designed to store any wearing effect on the motor and optionally display this effect. A number of motor starts and a number of operating hours, and optionally other operating characteristics relevant to the expected lifetime of an electric motor, are taken into account to obtain a decision regarding the reusability of the electric motor from a standpoint of product recycling. In addition, the knowledge of the status or state of these operating characteristics can be utilized in service/maintenance and market research. In particular, the reusability of the respective electric motor can be determined directly from a knowledge of the parameters, such as xe2x80x9cnumber of motor startsxe2x80x9d and xe2x80x9cnumber of hours of operationxe2x80x9d, without any expensive test procedures.
The means for the electric motor operating parameters acquisition device storing and displaying the effects of the operating parameters can be implemented in a number of different ways, e.g., as mechanical, electro-mechanical or electronic means based on physical, chemical or physicochemical effects. Such means is thus designed in the form of a liquid in a container, for example. This liquid is exposed to the heat of operation of the electric motor and is thereby evaporated, so that the recyclability of the electric motor can be determined at any time from the remaining amount of the liquid.
The means can also be provided in the form of an electronic circuit for recording the hours of operation and/or the number of starts of the electric motor, and preferably for recording both the hours of operation and the motor starts. Other operating parameters (e.g., power consumption, temperature, etc.) may also be recorded.
The circuit of the data acquisition device according to the present invention is provided with a time base on the basis of which the operating voltage and/or the motor starts is/are recorded. The time base may be an RC oscillator with a simple design (i.e., an oscillator without a quartz oscillator) because high accuracy and absolute time determination by the time base are not necessary.
Information regarding the hours of operation and the motor starts of the electric motor is preferably stored in a PROM or EPROM memory, the elements of which are written into or destroyed as a function of the motor start.
According to a further embodiment of the present invention, a read-write logic is also provided for storing the xe2x80x9cmotor startxe2x80x9d and xe2x80x9cmotor runxe2x80x9d states during the operating time of the electric motor.
The circuit of the data acquisition device according to the present invention may also have a readout circuit for stored operating parameters to permit a readout of the operating parameters via an appropriate external device and an optional analysis at the end of the operating time or when a decision is to be made about product recycling.
To be able to mount the data acquisition device according to the present invention on the respective electric motor without utilizing a large amount of space, the components of the circuit can be accommodated in an integrated circuit.
The present invention also relates to an electric motor equipped with the data acquisition device, which is preferably designed in the form of a module or integrated into the electric motor and may also have a diagnostic connection to permit a problem-free transfer of the operating parameters stored in the circuit to an external analysis device.